SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f32a740554b659cf9873561cfcbe500a298b2e070f0e60c6432295eae17302bd' 
  AND token = 'xW9S6Mklqg6pWAPzZ6qOWbJFx1AteXBYsGYGh11nK3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}